Regulator for air-compressors.



Patented Oct. 7, 1902'.

No. 7|0,'7l2.

w. PBELLWITZ. REGULATOR FUR AIR COMPBESSOBS.

(Application filed Nov. 13, 190;. (No Model.) 2' Sheeir-Shaat I I 4 Z n1: "cams PEYEF; culwu'rou'mo Wasniumu, o. c.

No. 7|0,7l2. Patented Oct. 7, I902.

W. PRELLWITZ.

REGULATOR FOR AIR CUMPBESSDRS.

(Application filed Nov. 13, 1901.) (No Model.) 2 Sheets-Sheet 2.

ii Mmiii Q wnaiweksi fiV/LJZ? Q? a i UNITED STATES PATENT OFFICE.

WVILIIIAM PRELLIVITZ, OF EASTON, PENNSYLVANIA, ASSIGN OR TO THE INGERSOLL-SERGEANT DRILL COMPANY, OF NEW YORK, N. Y., A CORPORATION OF WEST VIRGINIA.

REGULATOR FOR AlR-COMPRESSORS.

SPECIFICATION forming part of Letters Patent No. 710,712, dated October '7, 1902.

Application filed November 18,1901. Serial No. 82,073- (No model.)

T0 at whom, it may concern:

Be it known that 1, WILLIAM PRELLWITZ, a citizen of the United States, and a resident of Easton, in the county of Northampton, in the State of Pennsylvania, have invented a new and useful Improvement in Regulators for Air-Compressors, of which the following'is a specification.

This invention relates to that class of regulators for air-compressors which operate by more or less choking the inlet when the compression effected exceeds a certain degree.

The object of the improvement is to so retard under perfect control the closing and opening movements of theinlet-choking valve that the said movements will not be productive of any such jar on the motor or power plant by which the compressor is driven as is liable to be occasioned when the load of the compressor is thrown on or off suddenly; and to this end this improvement, which is applicable to either simple or multiple stage compressors, consists in the means hereinafter described and claimed for such control.

In the accompanying drawings the invention is illustrated as applied to whatis known as a piston-inlet compressor, which serves as well as any other for such illustration.

Figure 1 is a side view of the inlet end of the compressor-cylinder,with its fittings,and of the suction or air-inlet pipe through which air is supplied to said cylinder and shows the arrangement of the choking-valve and of my device for retarding and controlling the operation of said valve. Fig. 2 is an elevation of the inlet-pipe of the inlet-valve boX and valve and of the device for retarding and controlling the operation of the latter as viewed from the right of Fig. 1; Fig. 3, a vertical sectional view of the pipe, the valve, and the retarding and controlling device; Fig. at, a vertical sectional view, on a larger scale, of parts of the retarding and controlling device.

A designates the compressor-cylinder; B, the air-inlet pipe; 0, the hollow piston-rod working in stuffing-boxes ab in the cylinderhead and inlet-pipe, respectively. The inlet-pipe is represented as having an elbow, in the bend of which is the valve-box D, containing the choking or regulating valve E. This valve may be of any suitable kind, but is represented as of upright hollow cylindrical form, with ports 0, which register with ports 61 in the cylindrical seat provided for it in the box. It is represented as closing by an. upward movement.

On the top of the valve-box D is a small stationary upright hollow cylinder F, which is closed at the bottom, but open at the top, and in the lower part of which is an opening 6, which is to be in constant communication by a pipef with the receiver G, to which the compressed air is delivered. On the exterior of this cylinder F is fitted a cylinder H, which is closed at the top and which is connected with the valve E by rods g, which pass through openings in the top of the valvebox D outside of the cylinder F. The said cylinders F and H constitute two members between which the pressure of the air from the receiver entering the cylinder F at 6, acting against the closed top or head of the cylinder H, tends to lift and open the valve E. This tendency is more or less counteracted by a weight I, applied to a lever J, which is connected by an oscillating fulcrum h with the top of the valve-box D and which bears on knife-edge journals 'L' on the sides of said cylinder H, the said weight being so adjusted on the lever as to overcome the pressure in'the pipef until the said pressure exceeds the maximum desired,when the said pressure raises the cylinder H and produces the closing movement of the valve E.

On the closed upper end or head of the cylinder .H and carried thereby is a cylinder K, which is fitted with a piston L and which is filled with a liquid, as oil, above and below said piston. The said cylinder K has in it an outside port j, which forms communication between the spaces above and below its piston L. The rod 7a of the piston L passing through the top of the cylinder Kis screwthreaded and fitted to a female screw-thread in a bushing Z, which is secured in a stationary yoke it, supported by two posts k on the top of the valve-box. The screw-threaded rod 70 has its head suitably formed to be taken hold of and turned to adjust the piston higher or lower. The side port j of said cylinder K is fitted with an adjustable regulating-valve m to control the size of its passage. This valve is constituted by the end of a screw-threaded spindle m, which screws into the wall of the cylinder K and which projects through a stuffing-box n, outside of which'it is furnished with a head by which to turn it and adjust the valve. The said piston L and cylinder K, with the valve-controlled port j, constitute an adjustable double-actin g liquid dash-pot for controlling the opening and closing movements of the inlet choking-valve E, the piston L being held stationary by the rod 70. In the closing movement of the said valve E by the excessive pressure of the air upon the head of the cylinder H the liquid in the space below the piston L in the cylinder K has to be displaced through the portj to the space above said piston, and this displacement and the movement of the valve E is more or less retarded, according as the passage through the port j is more or less contracted by the adjustment of the valve m. In a corresponding manner the said adjustment .of the valve-m controls the displacement of the liquid in a downward direction through said port j and the slowness with which the valve opens. The closing of the valve E more or less, either completely or only partly, is controlled by the adjustment of the piston L more or less downward by the turning of its screw-threaded rod in the bushing l of the yoke 70, the said piston serving as a stop to the bottom of the liquid-cylinder K when the liquid has all been displaced from below to above said piston.

In applying the valve E and the controlling device herein described to a compound or multiple-stage compressorit is only necessary to apply them to the inlet of the low-pressure cylinder. In a duplex non-compound compressor they should be applied to the inlet of each air-cylinder.

By the term air as hereinabove employed I mean to include all gaseous or aeriform bodies.

What I claim as my invention is- 1. The combination with a valve for closing or choking the inlet to a compressor, of a stationary cylinder to which there is an inlet from the receiver to which the compressor delivers, a movable outer cylinder fitted to the exterior of said stationary cylinder, connections between said outer cylinder and the valve, and a double-acting liquid dash-pot the cylinder of which is carried by said movable cylinder and the piston of which has a stationary support,substantially as herein described.

2. The combination with a valve for closing or choking a com pressor-inlet, of a stationary cylinder for receiving air delivered by the compressor, a second cylinder fitted to the exterior of said stationary cylinder and having a closed outer end, rods outside of said stationary and second cylinders connecting said second cylinder with the valve, and a double-acting liquid dash-pot the cylinder of which is carried by said second cylinder and the piston of which has a stationary support, substantially as herein described.

3. The combination with a valve for closing or choking a compressor-inlet, of a stationary cylinder for receiving air delivered by the compressor, a second cylinder fitted to the exterior of said stationary cylinder and having a closed outer end and to which said valve is attached, a liquid-containing cylinder connected with said second cylinder and containing also a stationary piston between opposite sides of which within its containingcylinder there is a contracted communication, and means for adjusting said piston to stop the opening movement of the valve, substantially as herein described.

In testimony that I claim the foregoing as my invention I have signed my name, in presence of two witnesses, this 9th day of November, A. D. 1901.

WILLIAM PRELLWITZ.

Witnesses:

CHARLES T. MILLER, HARRY VAN BILLIARD. 

